1. FIELD OF THE INVENTION
The present invention relates to devices for cutting screw threads in the outer surfaces of round bars or tubes.
2. THE PRIOR ART
Threading devices for the cutting of screw threads in the outer surfaces of round bars or tubes are well known and normally include a die having internal cutting threads and a die stock in which the die is mounted, the die stock including opposed handles to enable it (and the die mounted therein) to be manually rotated. When the die is positioned against the end of the round bar or tube and rotated by means of the die stock, a screw thread will be cut into the round bar or tube. Many known die stocks are constructed to include guide means to assure that the axis of the die will remain aligned with the axis of the round bar or tube being operated on. However, die stocks that include such guide means are rather complicated in construction and tend to be expensive.
It is an object of the present invention to provide a threading device which is both simple in construction and inexpensive, and which does not require the use of a conventional die stock.
It is also an object of the present invention to provide a guide ring which can be attached to a conventional die to create a threading device that can be rotated around a round bar or tube by a hand wrench and will cut a uniform and symmetrical screw thread therein.